Isotretinoin is a retinoid (also known as 13-cis retinoic acid). Owing to its low water solubility, the oral bioavailability of isotretinoin is low. PCT Publication No. WO 00/25772 discloses that the presently marketed formulation of isotretinoin, i.e., Accutane®, contains isotretinoin at a mean particle size of about 100 μm resulting in only 20% oral bioavailability. Therefore, this application discloses a formulation of isotretinoin having a reduced particle size, thereby enhancing the oral bioavailability.
U.S. Pat. Nos. 7,435,427 and 8,367,102 cover the marketed formulation of Absorica®. These patents disclose capsules comprising a semi-solid suspension of isotretinoin containing at least two lipidic excipients, one having an HLB value equal to or greater than 10 and the other being an oily vehicle. These patents are based on the use of the “Lidose technology” to provide a formulation of isotretinoin with enhanced bioavailability.
The oral bioavailability of a drug is affected by various factors, which include aqueous solubility, absorption of drug through gastrointestinal tract, first pass effect, or food effect. The “food effect” as used herein means food-drug interactions which either decrease or increase the extent of drug absorption. Isotretinoin is known to have a food effect, i.e., its absorption is dependent on the presence of the food in the stomach. Therefore, there is a need to develop a composition of isotretinoin which exhibits a reduced food effect.